The 3rd Generation Partnership Project, 3GPP, is responsible for the standardization of the Universal Mobile Telecommunication System, UMTS, and Long Term Evolution, LTE. The 3GPP work on LTE is also referred to as Evolved Universal Terrestrial Access Network, E-UTRAN. LTE is a technology for realizing high-speed packet-based communication that can reach high data rates both in the downlink and in the uplink and is thought of as a next generation mobile communication system relative to UMTS. In order to support high data rates, LTE allows for a system bandwidth of 20 MHz, or up to 100 MHz when carrier aggregation is employed. LTE is also able to operate in different frequency bands and can operate in at least Frequency Division Duplex, FDD, and Time Division Duplex, TDD, modes.
In an UTRAN and an E-UTRAN, a User Equipment, UE, or a wireless device is wirelessly connected to a Radio Base Station, RBS, commonly referred to as a NodeB, NB, in UMTS, and as an evolved NodeB, eNodeB or eNB, in LTE. A Radio Base Station, RBS, or an access point/node is a general term for a radio network node capable of transmitting radio signals to a wireless device and receiving signals transmitted by a wireless device. In Wireless Local Area Network, WLAN, systems the wireless device is also denoted as a Station, STA.
In the 5th generation mobile networks, also referred to as 5G, there will be evolvement of the current LTE system. The main task of 5G is to improve throughput and capacity compared to LTE. This is achieved by increasing the sample rate and bandwidth per carrier. 5G is also focusing on the use of higher carrier frequencies, i.e. above 5-10 GHz.
In 5G, development takes one step further by connecting not only individuals but also all sorts of machines in real time. The Machine Type Communication, MTC, system should in particular allow for radio resource management that allows the coexistence between different classes of applications with operating characteristics such as; sporadic data, e.g., alert messages, periodic data, and others with e.g. real-time data (or simply best-effort data). These different types of applications have different requirements on the 5G network.
In view of Machine Type Communication, MTC, one requirement of the radio concepts to be used in 5G is to support low power devices. In a foreseeable future, billions of devices are expected to be connected through wireless networks generating the so called Internet of Things, IoT. Many of these are simple sensor devices that typically transmit small amounts of data seldom. One parameter that is vital for the enablement and success of IoT is power consumption. Ten years' longevity is a timeframe adopted by industry, which requires great resource frugality both in the communications modules as in the sensor or actuator modules of the device.
One further requirement on the radio concepts to be used in 5G is to support highly reliable ultra-low delay Machine-Type Communication, MTC, i.e., Critical-MTC. The Critical-MTC concept should address the design trade-offs regarding e.g., end-to-end latency, transmission reliability, system capacity and deployment, and provide solutions for how to design a wireless network for different industrial-application use cases. The Critical MTC system should in particular allow for radio resource management that allows the coexistence between different classes of applications: sporadic data, e.g., alert messages, periodic data, and others with e.g. real-time data (or simply best-effort data).
In cellular communication systems such as LTE, paging messages are used to page wireless devices being in idle mode about e.g. mobile terminated calls, i.e., to the wireless device incoming calls or data transmissions. Hence, paging is an important feature in idle mode operation. A paging message can also be used as a trigger for a wireless device to read system-information or to provide an indication from a public warning system.
In LTE, any data transmission succeeding the paging generally requires the wireless device to move from Idle Mode to Connected Mode, which results in a relatively large amount of signalling being exchanged between the wireless device and the network.
The currently proposed 5G specifications should allow adaptation of the present paging mechanisms to support certain special scenarios. This adaptation consists e.g. of repetition of paging messages for the purpose of coverage extension for low complexity/cost Machine Type Communication, MTC, devices or robustness improvement for wireless devices with extra-long Discontinuous Reception, DRX, cycles.
However, considering the diversity in terms of supported services, wireless device types, as well as deployments and use cases for 5G networks, further mechanisms aiming at defining communications mechanisms that enable optimizing network performance, despite the different requirements of the different types of applications and devices, are desirable.